Hydrostatic brake



0a. 24, 1939, c. SAUZ-EDDE 2,176,927

HYDROSTATIC BRAKE .Filed Jan. 13, 1936 INVENTOR (Vat/0f 54022 046 ATTORNEYS Patented Oct; 24, 1939 2,176,927 HYDROSTATIC BRAKE Claude Sauzedde, Detroit,

troit Hydrostatic Brake Micla, asslgnor to De- Corporation. Detroit,

Mich., a corporation of Michiganv Application January 13, 1936, Serial No.

10 Claims. (Cl. 188-452) The present invention relates. to hydrostatic brakes having shoes of sectional segmental form with dualconical faces adapted for wedging engagement with dual angularly disposed annular b contacting surfaces of a brake drum.

The primary object of the present invention is to provide a hydrostatic brake structure wherein the shoe supporting. and actuating means is particularly adapted to withstand; without distortion, the crushing and torsional stresses set up when the brake shoes with the braking surfaces of examplea preferred embodiment is disclosed wherein this object is attained by the provision 'of a brake shoe supporting spider having diametrically opposed co-axial guides supporting a pair of brake shoes of segmental form for radial movement with respect to a brake drum, the shoes being supported intermediate their ends by means which is slidably received in the guides on .the spider. The guides serve to support the brake'shoes in proper relation for braking engagement with the brake drum and resist the torsional stresses set up when the shoes are moved into engagement with the drum. The 'fluid'pressure brake shoe applying meansis disposed on diametrically opposite sides of the spider and between the ends of the brake shoes so that in addition to moving braking engagement with the drum surfaces they serve to reinforce the shoe guiding means and to relieve it of a part of the torsional stress resulting from brake application.

Another object of the present invention is to provide ahydrostatic brake having segmental shoes with dual conical faces for engagement with conical brake drum'surf'aces, means for supporting and guiding said shoes with respect to the drum whereby they may be moved into and out of engagement actuating means engagement with whereby torsional stresses set up by engagement of the shoes with the drum are uniformly distrlbuted'throughout the guides and the fluid pressure means.

This object is accomplished as will hereinafter appear by supporting the shoes intermediate their ends in'the guides and by applying the actuatinf Pressure of remote from the guides. This mode applying the pressure has the added advantage that Y the entire brake shoe surface engages underuniform pressure and thepressure which causes this engagement torsionally resists the 5.; heavyfriction present during brake engagement are forced into contact" of the drum. By way to the shoes at the en there-- the shoes into which ordinarily tends to carry the entire brake formation with the rotating braking surface.

Another object of the present invention is to provide a hydrostatic brake embodying a plurality of segmental type shoes with fluid pres- 5 sure means for causing engagement of the shoes with the brake drum, the fluid pressure means comprising expansible units disposed between the adjacent ends of the shoes so that when fluid is supplied thereto the pressure is 10 shoes, regardless of variations shoes irom their retracted position to a position of engagement, which length of travel might vary due to uneven wear on the shoes. 15 With the above and other ends in view the invention is more fully disclosed with reference to the accompanying drawing, wherein- Figure 1- is a vertical section of the brake, and Fig. 2 is a fragmentary section of a detail. Like characters of reference are employed throughout to designated corresponding parts.

Referring to Fig. l the numeral 1 designates an externally splined axle spindle and 2 a brake drum concentric therewith, the brake drum having braking surfaces 3 and 4 disposed obliquely to the axis thereof and opposed one to the other. As is well known in the art the axle spindle l is stationary and the brake drum 2 is rotatable with respect thereto, the latter being-adapted to 30 be attached to a wheel in the usual manner. On the spindle l is provided a spider 5 having a hub portion 8 internally splined to fit the splines on the spindle l. A vlded on diametrically opposite sides of the hub ,35 6, each guide comprising a pair of spaced apart arms 9 and Ill respectively. The arms 9 of the guide 1 and the arms "I of the guide 8 extend parallel to a diametric line passing centrally therebetween and through the axis of the hub 6. 40 A pair of brake shoes is provided and each shoe consists of obliquely disposedside members llv and 12 with brake lining material IS on 'the outer'conical faces thereof. The two side members H and I! are united intermediate their ends by a central uniting body ll having a portion extending inwardly radially with respect to the side members H and I2. The side members H and 12 are united adjacent one end by a transverse web it and at the other endby a web I1, the webs l6 and I! being rigid whereby they maintain the ends of the shoes in definitely spaced apart relation. l6 and i1 is a stem id provided a head IS. The face 20 of head 19 is Extending from each web at its end with provided with a series of radially extending ratchet-like other piston, is the bottom face of the shoulder 25. grooves or corrugations, these corrugations being Such movement-limiting means, although illusillustrated in the drawing in a greatly exagger trated herein, is not essential to the operation the guide 1 or between the arms I!) of the guide 8, tact when the brakes are fully retracted. Upon as the case may be. In each guide 1 and 8 there introduction of fluid under pressure into the passprings 22 normally move the shoes .inwardly 28 and 35, causing the latter to be forced apart. radially so as to be out of engagement with the By forcing the diaphragms 28 and 35 apart the 15 surfaces 3 and 4, v pistons 31 are likewise moved apart and press the The spider 5 has a pair of cylindrical chambers .shoes into engagement with the brake .surfaces 3 23 a d 24 ormed on diametrically opposite sides of. and 4. It will thus be seen that the heads l9 and to each other and the guides 1 and 8. Inasmuch erating ratchet faces thereon tend to prevent rota- 20 23 and 24 is identical, only that in the chamber 23 39 ofthe pistons. However, by applying rotative is illustrated and described in detail. The champressure to any of the heads 4| by engaging a ber 23 has an internal shoulder 25 upon which is suitable implement in the peripheral notches 25 seated an annular metallic member 26 having thereof the stems 40 may be rotated and screwed 25 I serrations 21 in the inner surface thereof and an into or out of their respective pistons for the elastic diaphragm 28 vulcanized thereto. Resting purposes of adjustment. upon the top of the annular member 26 is an Although a specific embodiment of the invenaluminum seal' 29, also of annular form. A ring tion has been illustrated and'described it will be 30 30 having a peripheral groove 3| and a seriesof understood that various changes may be made 30 29. Resting on the ring 39 is an aluminum seal 33 such changes are contemplated. of annular form and engaged by an annular mem- What I claim is:

35 ber 34, similar to the annular member 26, and hav- 1. Supporting means for hydrostatic wheel 35 ing an elastic diaphragm 35 vulcanized thereto. braking m h n Comprising a spider, id The annular member 34, seal 33, 'ring 30, seal 29 sp der having a C a y d p d hub Dart, brake and annular member 26 are all tightly clamped toshoe guide members integral with said hub, said gether by a retainer 36 which is screwed into the de embe s be dispo d With he axes 40 end of the cylindrical chamber 23, It ill b coincident withadiametric line extending through 40 Received in each of the diaphragms 28 and 35 is their axes p a e to s d diametrl'c ne- 45 a piston 31, each piston being internally threaded 2. Supp t ng means for hydrostatic W eel at 39 to receive a'screwthreaded stem 40 having a, brakingmechanisms comprising a cross-shaped periphery thereof and with a series of ratchet-like said hub portion and disposed in opposed portions 5 heads l9 rests upon one of the heads 4|. 3 of said spider and symmetrically spaced with re in there is provided a plug 41 having passages 48 chambers.

Upon reference to Fig. 1 it will be seen that'reinspider, said spider having a centrally disposed hub forcing webs 49 extend from the guide arms 9 and partintegral with the cross portions, brake shoe 5 III to the cylindrical chambers 23 and 24 sothat guide members in opposed cross portions, said fltlli guides and chambers mutually reinforce each J guide members being disposed with their axes 0 er.

ally and to force the diaphragms 28 and 35 toward spaced relation to said guides and disposed with 70 between the diaphragms. The pistons 31 move connections between the cross portions having inwardly until their flanged ends engage positive saidguides and the cross portion having said movement limiting means which, with one of the cylindrical chambers and mutually bracing the pistons, is the sealing element 36, and with. the same. 75

4. Supporting means for hydrostatic wheel braking mechanisms comprising a cross-shaped spider, said spider having a centrally disposed hub portion adapted for the reception of supporting means, guide members in opposed cross portions of said spider, each guide comprising a pair of arms projecting from arms parallel to a line extending diametrically through said hub, a pair of formed in the other cross portions of said spider and equally spaced from said guides and disposed with their axes parallel to said diametric line, and web connections between the cross portions having said guides and the adjacent cross portions having said cylindrical chambers and mutually bracing the same.

5. In a hydrostatic wheel braking mechanism, a rotatable drum, a stationary support, a plurality of brake shoe members, cooperating means on said stationary support and brake shoe members supporting said shoe members, said means including elements for guiding said shoe members radially of the drum and for preventing angular movement of the shoe members about their axes of movement while said shoe members remain substantially unsecured against movement in the direction of the axis of said drum, yieldable means normally urging said shoes inwardly with respect to said drum, and hydrostatically expansible means between the ends of said shoes for moving them outwardly with respect to said drum.

6. In a hydrostatic wheel braking mechanism, a rotatable drum having a pair of opposed braking surfaces extending obliquely to the axis of rotation thereof, a spider stationary with respect to said drum, a plurality of brake shoes having opposed braking surfaces extending at an oblique angle corresponding to the braking surfaces on said drum, guide means on' sa'd spider supporting said brake shoes for movement and for guiding such movement radially into and out of engagement with said drum braking surfaces with said shoes substantially unsecured against move- 'ment in the direction of the axis of said drum,

yieldable means normally retracting said shoes from engagement with said drum surfaces, and hydrostatically expansible means supported by said spider and disposed thereby between the ends of said shoes for moving said shoes into engagement with said drum surfaces.

7. In a hydrostatic wheel braking mechanism, a rotatable drum having a pair of opposed brakingsurfaces extending obliquely to the axis of rotation thereof, a spider stationary with respect to said drum, a plurality of brake shoes having opposed braking surfaces extending at an oblique anglecorresponding to the braking surfaces (n said drum, guide means on said spider supporting said brake shoes for radial movement into and 'out of engagement with said drum braking surfaces with said shoes substantially unsecured against movement in the direction of the axis of said drum, yieldable means normally retracting the hub with each pair having its cylindrical chambers said shoes from engagement with said drum surfaces, hydrostatically expansible means supported by said spider and disposed thereby between the ends of said shoes for moving said shoes into engagement with said drum surfaces, and means manually adjustable as to length freely connecting said hydrostatically expansible means with adjacent ends of respective shoes.

8. In a hydrostatic wheel braking mechanism, a rotatable drum, a stationary support having radial guides disposed radially with respect to said drum, segmental shoes supported by said guides and movable in said guides radially into and out of engagement with said drum, said guides comprising spaced parallel arms and said shoes being substantially unsecured against movement relative to the arms in the direction of the axis of said drum, fluid receiving members supported by said stationary support, pistons freely connected to opposite ends of said shoes and slidably received in said chambers, means for supplying fiuid under pressure to said chambers, and yieldable means normally holding said shoes out of engagement with said drum.

9. In a hydrostatic wheel braking mechanism, a rotatable drum, a stationary support coaxial with said drum, a pair of diametrically opposite guides on said support, brake shoe members supported in said guides for radial movement with respect to saiddrum, said guides being open at their sides whereby the shoes are unsecured against movement in the direction of the axis of said drum, a pair of fluid receiving cylindrical chambers on said support disposed on diametrically opposite sides thereof, said cylindrical chambers being disposed with their axes parallel to the axes of the guides,'a pair of movable elements in each chamber, means freely connecting each movable element to one end of a brake shoe, said connecting means including elements permitting relative movement between said movable elements and brake shoes, fluid conveying means opening into said chambers between the movable elements therein, and yieldable means for moving said shoes inwardly with respect to said guides.

10. Supporting means for hydrostatic wheel braking mechanisms comprising a spider, said spider having a centrally disposed hub portion adapted for reception of supporting means, guide members integral with said hub, each guide comprising a pair of arms projecting from the hub with each pair having its arms parallel to a line extending diametrically through said hub, said arms being adapted to restrict movement of brake shoesv received therein to a direction radial with respect to said hub portion while the shoes remain substantially unsecured against movement in the direction of the axis of said hub portion, a pair of cylindrical chambers formed on diametrically opposite sides of said hub and equally spaced from said guides and disposed with their axes parallel to said diametrlc line.

CLAUDE BAUZEDDE. 

